Working the first round of the NFL Draft even harder than movie counterpart Kevin Costner did in “Draft Day,” the Browns ended all the suspense Thursday night by taking Texas A&M quarterback Johnny Manziel with the No. 22 pick.

Pass-rush terror Jadeveon Clowney was the first choice overall, going to the Texans after Houston found no takers for the spot, but it was the fate of the polarizing Manziel that transfixed the football world for nearly three hours until Cleveland finally stepped in.

The Browns, who have a first-year general manager in Ray Farmer and a first-year coach in ex-Jets defensive coordinator Mike Pettine, ended Manziel’s televised agony by making their third trade of the first round to get him.

The quarterback drama didn’t end with Manziel, either.

An opening round that turned sleepy after the Browns’ second pick during a run of defensive backs ended with a bang as the Vikings traded with the Seahawks to take Louisville’s Teddy Bridgewater with the night’s 32nd and final selection.

But Bridgewater’s fall didn’t transfix the Radio City Music Hall crowd nearly as much as the Manziel saga.

Cleveland began the night with two first-round picks and dealt the second of them (No. 26) and a third-rounder this year to Chip Kelly’s Eagles to move up four spots and take the player who had been the Browns’ original target at No. 4 overall.

The crowd, which had been chanting “Johnny! Johnny!” while the Browns were on the clock, erupted in cheers when NFL commissioner Roger Goodell finally stepped up to the podium and announced Manziel’s name.

The Browns’ decision came after 21 players were taken before Manziel, including two of his college teammates (offensive tackle Jake Matthews by Atlanta at No. 6 and wideout Mike Evans by Tampa Bay at No. 7).

The Manziel melodrama reached its fever peak when the Cowboys’ pick at No. 16 overall approached. Owner Jerry Jones had made no secret of his admiration for the Texas-born Manziel, and sources said Jones had to be talked into taking Notre Dame offensive lineman Zack Martin instead.

Manziel sounded relieved the Cowboys passed on him.

“I don’t know if the world could’ve handled that, honestly,” he said of the possibility of going to Dallas.

Manziel certainly won’t lack for competition in Cleveland, though. The Browns’ incumbent starter is promising young pro Brian Hoyer, and the club also recently signed a host of backups that include Vince Young.

Meanwhile, the wait for the first major surprise of the draft wasn’t long as the Jaguars daringly took late-rising Central Florida quarterback Blake Bortles with the No. 3 pick.

Bortles, who looks the part at 6-foot-5, 232 pounds, but essentially had just one good season in college, was a choice out of left field only because there had been zero talk of him in connection to Jacksonville.

The Jaguars’ unexpected move was immediately followed by another shocker, when the Bills — who are changing owners soon in the wake of Ralph Wilson’s recent death — decided to go for broke and mortgage next year’s draft for Clemson wideout Sammy Watkins.

Buffalo traded its first-rounder this year (No. 9) and first- and fourth-rounders next year to move up to No. 4 in order to pair the talented Watkins with Stevie Johnson and give young quarterback EJ Manuel a potent receiving corps.

The Texans tried to inject some suspense into the start of the draft, but no one was buying.

Houston used its entire time allotment waiting for a trade offer that never came before going for the sure thing in South Carolina’s Clowney.

Defying local sentiment to take Manziel, the Texans went with the consensus choice as the best player in the entire draft in Clowney, a 6-foot-6, 270-pound terror with long arms and freakish athleticism.

Houston will now pair Clowney with former NFL Defensive Player of the Year J.J. Watt for what on paper is arguably the most imposing defensive line in the entire league.

Sources said the Texans were open to trading out of the top spot but drove too hard of a bargain, with GM Rick Smith wanting three first-rounders and two second-rounders for the spot.